Seat apparatus for vehicle

ABSTRACT

A seat apparatus for a vehicle including a side support portion that is controlled to be opened and closed depending on a road shape includes a position detecting portion for detecting a position of the side support portion, a sensor provided at the side support portion and detecting a physique of an occupant, a physique detecting portion for detecting the physique of the occupant by means of the sensor while the side support portion is in a full open position, and an initial position determining portion for determining an initial position of the side support portion depending on the physique of the occupant detected by the physique detecting portion.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 U.S.C. §119 toJapanese Patent Application No. 2006-319614, filed on Nov. 28, 2006, theentire content of which is incorporated herein by reference.

FIELD OF THE INVENTION

This invention generally relates to a seat apparatus for a vehicle. Moreparticularly, this invention pertains to a seat apparatus for a vehiclethat controls a side support portion depending on a road shape.

BACKGROUND

A known seat apparatus for a vehicle is disclosed in JP2590875B. Theseat apparatus disclosed includes a capacitance sensor for determiningwhether or not an occupant is seated on a seat so as to perform an openand close control on a side support portion. According to the seatapparatus disclosed, the capacitor sensor is used only for determiningpresence or absence of an occupant and is not used for changing,depending on the physique of an occupant, a support position of the sidesupport portion, i.e., a position where the upper body of an occupant issupported thereby.

On the other hand, JP63-033849U discloses a seat apparatus for a vehicleincluding a pressure sensor provided at a side support portion fordetecting the physique of an occupant. A support position of the sidesupport portion, i.e., a position where the upper body of an occupant issupported thereby, can be adjusted on the basis of a pressure valuedetected by the pressure sensor. The support position of the sidesupport portion can be changed depending on the physique of an occupant.

According to the seat apparatus disclosed in JP63-033849U, however, theside support portion should be brought to a closed position at a timethe physique of an occupant is being detected by means of the pressuresensor, which may give an oppressive feeling to the occupant. Further,the side support portion should be opened or closed to obtain anappropriate position after the physique of the occupant is detected withthe side support portion in the closed state, thereby requiring time.

Thus, a need exits for a seat apparatus for a vehicle which is notsusceptible to the drawback mentioned above.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, a seat apparatus for avehicle including a side support portion that is controlled to be openedand closed depending on a road shape includes a position detectingportion for detecting a position of the side support portion, a sensorprovided at the side support portion and detecting a physique of anoccupant, a physique detecting portion for detecting the physique of theoccupant by means of the sensor while the side support portion is in afull open position, and an initial position determining portion fordetermining an initial position of the side support portion depending onthe physique of the occupant detected by the physique detecting portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and additional features and characteristics of the presentinvention will become more apparent from the following detaileddescription considered with reference to the accompanying drawings,wherein:

FIG. 1 is a perspective view of a seat apparatus for a vehicle accordingto an embodiment of the present invention;

FIG. 2 is a plan view of the seat apparatus according to the embodimentof the present invention;

FIG. 3 is a diagram illustrating a capacitance sensor according to theembodiment of the present invention;

FIG. 4 is an electric connection diagram of the seat apparatus accordingto the embodiment of the present invention;

FIG. 5 is a diagram illustrating an output pulse of support positionsensors according to the embodiment of the present invention;

FIG. 6 is a flowchart illustrating an initial position setting programaccording to the embodiment of the present invention; and

FIGS. 7A and 7B are each diagram illustrating a relationship between thenumber of pulses and an initial position according to the embodiment ofthe present invention.

DETAILED DESCRIPTION

An embodiment of a seat apparatus for a vehicle (hereinafter referred toas a seat apparatus) related to the present invention will be describedin accordance with the attached drawings. As illustrated in FIG. 1, theseat apparatus includes a seat slide device 10 and a seat 13. The seatslide device 10 includes, for example, a pair of lower rails 11 and apair of upper rails 12 supported by the lower rails 11 so as to beslidable thereon. The lower rails 11 are fixed on a floor 90 so as toextend in a front-rear direction of the vehicle. Specifically, the seat13 includes a seat cushion 14 on which an occupant is seated, and a seatback 15 that supports the occupant's back. Further, a right side supportportion 16 and a left side support portion 17 are provided at right andleft portions of the seat back 15, respectively, for stabilizing aposture of the occupant by pressing the upper body of the occupant onits sides. Additionally, as illustrated in FIG. 1, a right motor 26 anda left motor 27 are provided at right and left portions of a seat frame18, respectively. Each of the right and left motors 26 and 27 includes areduction mechanism. Furthermore, a right support frame 16a and a leftsupport frame 17 a are adapted to be pivoted by means of the right andleft motors 26 and 27, respectively. Both right and left support frames16 a and 17 a are pivoted by both right and left motors 26 and 27 beingactivated, and therefore the right and left side support portions 16 and17 are moved to be in an open position, which is indicated with a solidline, and to be in a closed position, which is indicated with a chaindouble-dashed line illustrated in FIG. 2. Furthermore, as illustrated inFIG. 1, a belt anchor 9 including a buckle 8 is fixed to a rear endportion of one of the upper rails 12. The buckle 8 accommodates aseatbelt sensor 22 that detects whether or not the seatbelt is fastened(i.e., buckled). The right side support portion 16 and the left sidesupport portion 17 collectively serve as a side support portion.

Specifically, each of the side support portions 16 and 17 includes afixed portion and a movable portion. The respective movable portions ofthe side support portions 16 and 17 are pivoted in response toactivation of the right and left motors 26 and 27, respectively. Then, aright sensor electrode 24 a and a left sensor electrode 24 b arearranged at the respective movable portions of the side support portions16 and 17 so as to form a part of a capacitance sensor 24. Precisely, asillustrated in FIG. 3, the capacitance sensor 24 is provided formeasuring a capacitance formed between the sensor electrodes 24 a and 24b, and an occupant, and a capacitance formed between the occupant and asensor ground 24 c connected to a chassis so as to detect the physiqueof the occupant. The capacitance sensor 24 serves as a sensor.

FIG. 4 illustrates an electric connection diagram of the seat apparatus.As illustrated in FIG. 4, the seat apparatus includes a physiquedetection ECU 20 and a side support ECU 21. The seatbelt sensor 22 andthe capacitance sensor 24 are connected to the physique detection ECU20. The seatbelt sensor 22 detects whether or not the seatbelt isfastened, (i.e., buckled) and then outputs a signal indicating thedetection result, i.e., seatbelt status signal, to the physiquedetection ECU 20. In addition, the capacitance sensor 24 measures thephysique of an occupant as mentioned above.

The right motor 26, the left motor 27, a right position sensor 28, and aleft position sensor 29 are all connected to the side support ECU 21.The side support ECU 21 outputs driving signals to both the right andleft motors 26 and 27, and inputs pulse signals serving as positionsignals from both the position sensors 28 and 29. The side support ECU21 and the physique detection ECU 20 are connected to each other so thatinformation can be shared and transmitted therebetween.

As illustrated in FIG. 5, the right and left position sensors 28 and 29each output, for example, 0 to 300 pulses depending on the position ofthe side support portions 16 and 17 within a range from a full closedposition to a full open position. The side support ECU 21 monitors andcalculates the output pulses from the position sensors 28 and 29 tothereby detect the position of the side support portions 16 and 17.

A process for setting an initial position of the side support portions16 and 17 according to the aforementioned seat apparatus will beexplained below. A ROM in the physique detection ECU 20 stores aninitial position setting program as illustrated in FIG. 6 conducted perpredetermined time interval.

In the cases where the initial position setting program illustrated inFIG. 6 is started, the physique detection ECU 20 obtains variousinformation in step S10. Precisely, the physique detection ECU 20 inputsa signal indicating whether or not the seatbelt is fastened (i.e.,seatbelt status signal) from the seatbelt sensor 22 and positioninformation of the side support portions 16 and 17 from the side supportECU 21. That is, at this time, the side support ECU 21 is conducting aside support control program (not shown) so as to obtain positioninformation of the side support portions 16 and 17 based on the pulsesignals input from the position sensors 28 and 29. Then, the physiquedetection ECU 20 inputs the position information of the side supportportions 16 and 17 from the side support ECU21. The step S10, the rightposition sensor 28, and the left position sensor 29 collectively serveas a position detecting portion.

In step S11, the physique detection ECU 20 determines whether or not atrigger signal for the physique detection is present. In the cases wherethe trigger signal is present (i.e., YES as indicated by “Y” in FIG. 6),a process in step S12 is then performed. In the cases where the triggersignal is not present (i.e., NO as indicated by “N” in FIG. 6), theexecution of the initial position setting program is terminated. As thetrigger signal, the seatbelt status signal from the seatbelt sensor 22is used. Only in the cases where the seatbelt is fastened for the firsttime from a state where the seatbelt is not fastened, it is determinedthat the trigger signal is present. Accordingly, in the cases where theseatbelt is not fastened or the seatbelt is already fastened, it isdetermined that the trigger signal is not present. Alternatively, as thetrigger signal for the physique detection, a drive range switch signalof a shift lever may be used. That is, it is determined that the triggersignal is present only when the shift lever is shifted to the driverange for the first time after the ignition switch is turned on.

In step S12, the physique detection ECU 20 determines whether or not theside support portions 16 and 17 are in the full open position. When itis determined that the side support portions 16 and 17 are in the fullopen position (i.e., YES), a process in step S13 is then performed. Onthe other hand, when it is determined that the side support portions 16and 17 are not in the open position (i.e., NO), the execution of theinitial position setting program is terminated. At this time, whether ornot the side support portions 16 and 17 are in the full open position isdetermined through the position information of the side support portions16 and 17 input from the side support ECU 21 in the step S10.

In step S13, the physique detection ECU 20 detects the physique of anoccupant by means of the capacitance sensor 24. In step S14, thephysique detection ECU 20 obtains initial position information of theside support portions 16 and 17 based on the detected physique by usinga table prepared beforehand, and then outputs that initial positioninformation to the side support ECU21. The physique detection ECU 20terminates the initial position setting program after executing theprocess in step S14. At this time, according to the present embodiment,the initial position information is obtained by means of the tableprepared beforehand. Alternatively, the initial position information maybe obtained by calculation. The initial position of the side supportportions 16 and 17 is defined to be on a slightly full open side of asupport position where the upper body of an occupant is pressed fromboth sides so as to support and stabilize a sitting posture of theoccupant. That is, the initial position is defined to be a positionwhere the side support portions 16 and 17 can be immediately activatedto the support position. In addition, the initial position informationis equal to the number of pulses outputted from the position sensors 28and 29 while the side support portions 16 and 17 are controlled to beclosed from the full open position to reach the initial position by theside support ECU 21. The step S13 serves as a physique detectingportion, and the step S14 serves as an initial position determiningportion.

Then, the side support ECU 21 outputs the driving signals to the rightand left motors 26 and 27 based on the initial position information sothat the side support portions 16 and 17 are specified to be in theinitial position. When a vehicle starts driving, the side supportportions 16 and 17 are controlled to be opened and closed by the sidesupport ECU 21 in response to the lateral acceleration of the vehiclewithin a range between the initial position and the support position.

Next, an application example of the initial position setting programwill be explained with reference to FIGS. 7A and 7B. FIG. 7A illustratesan example in which an occupant having obese physique is seated whileFIG. 7B illustrates an example in which an occupant having slim physiqueis seated. In both examples illustrated in FIGS. 7A and 7B, the supportposition where the upper body of the occupant is pressed from both sidesso as to support a sitting posture of the occupant is defined to be arange of 150 pulses that are outputted from the position sensors 28 and29 as illustrated by arrows in FIGS. 7A and 7B. In addition, 30 pulsesare defined between the initial position and one end of the supportposition close to the full open position.

In the cases where the occupant sits down on the seat cushion 14 andfastens the seatbelt, it is determined that the trigger signal for thephysique detection is present in the step S11. Then, when the sidesupport portions 16 and 17 are in the full open position at that time,the physique of the occupant is detected in the step S13. Further, inthe step S14, the number of pulses generated in response to theoccupant's physique is obtained as initial position information that isthen input to the side support ECU 21. The number of pulses as theinitial position information is sixty in the example illustrated in FIG.7A or ninety in the example illustrated in FIG. 7B.

Meanwhile, the side support ECU 21, which is executing the side supportcontrol program, controls the side support portions 16 and 17 to be inthe initial position based on the initial position information inputfrom the physique detection ECU 20. When the vehicle starts driving, theside support portions 16 and 17 are controlled to be opened and closedby the side support ECU 21 in response to the lateral accelerationwithin the range between the initial position and the support position.

According to the aforementioned seat apparatus, the initial position ofthe side support portions 16 and 17 is determined in the step S14 basedon the physique of the occupant detected in the step S13. On the basisof the initial position determined, the side support portions 16 and 17are controlled to be opened and closed depending on a road shape.Further, in the step S13, the physique of the occupant is detected whilethe side support portions 16 and 17 are in the full open state. That is,the side support portions 16 and 17 are not required to be closed at atime of detecting the occupant's physique. Thus, according to thepresent seat apparatus, the support position can be changed in responseto difference in the physique of an occupant. In addition, the physiqueof an occupant can be detected within a short time period without addingan oppressive feeling to the occupant.

In addition, according to the aforementioned seat apparatus, thecapacitance sensor 24, precisely, the sensor electrodes 24 a and 24 b,is provided at the movable portions of the side support portions 16 and17 to thereby appropriately detect the physique of an occupant. Further,since the physique of an occupant is detected at a time the occupantfastens the seatbelt, the physique substantially same as that in thevehicle driving state can be detected.

Further, according to the aforementioned embodiment, since thecapacitance sensor 24 is provided for the physique detection, thephysique of an occupant can be detected while the right and left sidesupport portions 16 and 17 are in the full open position.

Furthermore, according to the aforementioned embodiment, the capacitancesensor 24 is provided at a movable portion of the side support portion16 or 17.

Furthermore, according to the aforementioned embodiment, the physique ofthe occupant is detected by the position sensors 28 and 29, and throughthe step S14 in a case where the occupant fastens a seatbelt.

Furthermore, according to the aforementioned embodiment, the physique ofthe occupant is detected by the position sensors 28 and 29, and throughthe step S14 in a case where a shift lever is shifted to a drive range.

The principles, preferred embodiment and mode of operation of thepresent invention have been described in the foregoing specification.However, the invention which is intended to be protected is not to beconstrued as limited to the particular embodiments disclosed. Further,the embodiments described herein are to be regarded as illustrativerather than restrictive. Variations and changes may be made by others,and equivalents employed, without departing from the spirit of thepresent invention. Accordingly, it is expressly intended that all suchvariations, changes and equivalents which fall within the spirit andscope of the present invention as defined in the claims, be embracedthereby.

1. A seat apparatus for a vehicle including a side support portion thatis controlled to be opened and closed depending on a road shape,comprising: a position detecting portion for detecting a position of theside support portion; a sensor provided at the side support portion anddetecting a physique of an occupant; a physique detecting portion fordetecting the physique of the occupant by means of the sensor while theside support portion is in a full open position; and an initial positiondetermining portion for determining an initial position of the sidesupport portion depending on the physique of the occupant detected bythe physique detecting portion.
 2. A seat apparatus according to claim1, wherein the sensor is equal to a capacitance sensor.
 3. A seatapparatus according to claim 1, wherein the sensor is provided at amovable portion of the side support portion.
 4. A seat apparatusaccording to claim 2, wherein the sensor is provided at a movableportion of the side support portion.
 5. A seat apparatus according toclaim 1, wherein the physique detecting portion detects the physique ofthe occupant in a case where the occupant fastens a seatbelt.
 6. A seatapparatus according to claim 2, wherein the physique detecting portiondetects the physique of the occupant in a case where the occupantfastens a seatbelt.
 7. A seat apparatus according to claim 3, whereinthe physique detecting portion detects the physique of the occupant in acase where the occupant fastens a seatbelt.
 8. A seat apparatusaccording to claim 4, wherein the physique detecting portion detects thephysique of the occupant in a case where the occupant fastens aseatbelt.
 9. A seat apparatus according to claim 1, wherein the physiquedetecting portion detects the physique of the occupant in a case where ashift lever is shifted to a drive range.
 10. A seat apparatus accordingto claim 2, wherein the physique detecting portion detects the physiqueof the occupant in a case where a shift lever is shifted to a driverange.
 11. A seat apparatus according to claim 3, wherein the physiquedetecting portion detects the physique of the occupant in a case where ashift lever is shifted to a drive range.
 12. A seat apparatus accordingto claim 4, wherein the physique detecting portion detects the physiqueof the occupant in a case where a shift lever is shifted to a driverange.